The influence of local surface winds on air pollution concentrations at curbside monitoring stations and its consequences for modelling | The Meteorological Society of New Zealand

The influence of local surface winds on air pollution concentrations at curbside monitoring stations and its consequences for modelling

Year: 
2005
Volume: 
24
Author(s): 
K.N. Dirks
A.P. Sturman
Abstract: 

This paper investigates the surface wind variations at a suburban air quality monitoring station located in Hamilton, New Zealand and its impact on air pollution levels. Site-specific wind speed and direction information is found to be important, due to valley winds generated by a nearby basin of the Waikato River that passes through Hamilton City. Wind shifts due to the resulting valley winds were seen to lead to 180º wind direction changes that frequently coincide with the peak morning traffic and hence peak air pollution concentrations. This suggests that attempts at modelling vehicle-generated pollution need to either incorporate the valley winds into the model (with accurate representations of the timing of the wind shifts) or use wind information collected at the site. The results of a semi-empirical model presented here suggest that hourly averages are adequate for predicting pollutant concentrations, even under conditions such as those experienced in Hamilton where there are significant wind direction shifts at peak traffic times.

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